What's causing those high bacteria readings at your local beach? A sanitary survey is one tool that can be used to help answer that question.
A sanitary survey is a method of investigating the sources of fecal contamination to a water body. Sanitary surveys are typically used for drinking water, shellfish, and watershed protection programs. They can also be used at beaches. Sanitary surveys help state and local beach program managers and public health officials identify sources of beach water pollution, assess the magnitude of pollution, and identify priority locations for water testing.
Beach sanitary surveys involve collecting information at the beach, as well as in the surrounding watershed. Information collected at the beach may include: number of birds at the beach, slope of the beach, location and condition of bathrooms, and amount of algae on the beach. Information collected in the watershed may include: land use, location of storm water outfalls, surface water quality, and residential septic tank information. Beach managers can use the sanitary survey results to prioritize state or county resource allocations to help improve beach water quality. The initial sanitary survey may identify locations that can be further tested for possible illicit connections or illicit discharges. In addition, they may be able to use sanitary survey data (e.g., bacteria levels, source flow, turbidity, rainfall) to develop models to predict beach water quality using readily available data.
EPA developed a beach sanitary survey tool, one each for marine and Great Lakes beaches, to help beach managers evaluate all contributing beach and watershed information including water quality data, pollution source data, and land use data. The tool consists of three types of beach sanitary surveys, in paper and electronic form. See below for EPA guidance materials and beach survey forms. There are also other great resources on sanitary surveys including this presentation by the CA Water Quality Monitoring Council, and this guide by the Maine Healthy Beaches Program.
Marine Beach Sanitary Surveys
EPA originally developed sanitary survey materials for Great Lakes beaches. They have now updated their beach sanitary survey tool to include survey forms that can be used at marine beaches. The survey forms include detailed questions on winds, tides, and other characteristics that affect marine beaches and were not included on the surveys for the Great Lakes.
This EPA website has additional information on sanitary surveys, as well as factsheets and forms for sanitary surveys at Great Lakes beaches.